<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style>
        div {
            width: 1210px;
            margin: 200px auto;
            color: red;
            text-align: center;
            font: 600 30px/30px "simsun";
        }
    </style>
</head>
<body>
    <div></div>

<script>
    var div=document.getElementsByTagName("div")[0];
    var timer = setInterval(fn,1);
    function fn(){
        var nowtime = new Date();
        var future = new Date("2016/09/05 18:23:15");
        var timeSum = future.getTime() - nowtime.getTime();
        var day = parseInt(timeSum/1000/60/60/24);
        var hour = parseInt(timeSum/1000/60/60%24);
        var minu = parseInt(timeSum/1000/60%60);
        var sec = parseInt(timeSum/1000%60);
        var millsec = parseInt(timeSum%1000);
        day=day<10?"0"+day:day;
        hour=hour<10?"0"+hour:hour;
        minu=minu<10?"0"+minu:minu;
        sec=sec<10?"0"+sec:sec;
        if(millsec<10){
            millsec="00"+millsec;
        }else if(millsec<100){
            millsec="0"+millsec;
        }
//
//        console.log(day);
//        console.log(parseInt(timeSum/1000/60/60/24));
        if(timeSum<0){
            div.innerHTML="距离苹果发布会还有00天00小时00分00秒000毫秒";
            clearInterval(timer);
            return;
        }
        div.innerHTML="距离苹果发布会还有"+day+"天"+hour+"小时"+minu+"分"+sec+"秒"+millsec+"毫秒";
    }

</script>
</body>

</html>